1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device, and more particularly, to an LCD device having molding-type substrates formed so as to have a controllable thickness through simplified fabricating processes.
2. Background of the Invention
In general, flat type display devices have been continuously developed as media to transmit visual information since the beginning of the 21st century. Among the various flat type display devices, liquid crystal display (LCD) devices are being spotlighted as the next generation cathode ray tube (CRT). In the LCD device, data signals are individually supplied to pixels arranged in the form of matrixes according to image information, and optical transmittance of each pixel is controlled, thereby displaying a desired image.
However, the LCD device can not spontaneously emit light therefrom, thereby requiring a backlight to additionally provide light for displaying an image. The backlight may have various types. However, the backlight may be largely divided into an edge type and a direct type according to a structure that a lamp is installed in the backlight. The edge type indicates a backlight provided with one lamp at one side, or a backlight provided with two lamps at both sides. On the contrary, the direct type indicates a backlight having a plurality of lamps therebelow. Here, the lamp may include a cold Cathode Fluorescent Lamp (CCFL), or an External Electrode Fluorescent Lamp (EEFL).
FIG. 1 is an exploded perspective view showing a direct type LCD device in accordance with the conventional art.
As shown in FIG. 1, a reflection plate 42 for reflecting light supplied from a plurality of lamps 50, a light source, to a front surface of an LC panel 10 is attached onto a lower cover 40. The plurality of lamps 50 are fixed onto the reflection plate 40 by a fixing member (not shown). On the reflection plate 42, provided are a diffusion plate 44 for uniformly and forwardly distributing light reflected through the reflection plate 42, and optical sheets 36 for complementing an optical characteristic of light passing through the diffusion plate 44.
A main support 30 for balancing an entire force of the LCD device is laminated on the optical sheets 36. Here, the main support 40 is formed to have a pattern with consideration of the LC panel 10 to be laminated thereon.
The LC panel 10 laminated on the main support 30 is formed by undergoing many unit processes. That is, the LC panel 50 includes an array substrate, a switching device having a thin film transistor at each unit pixel; a color filter substrate having a color filter that represents colors; and an LC injected between the two substrates.
An upper cover 20 that covers an outer periphery of the LC panel 10 and side surfaces of the main support 30 is coupled to the lower cover 40 by an additional coupling means such as hooks.
As a fixing member for fixing the plurality of lamps 50 laminated on the lower cover 40, approximately 16 lamps are arranged in a constant gap therebetween for high brightness in case of an LCD TV having a large screen of 32 inches, whereas approximately 20 lamps are arranged in case of an LCD TV having a large screen of 40 inches.
FIG. 2 is a view showing a cold Cathode Fluorescent Lamp (CCFL) provided at a fixing member, and FIG. 3 is a view showing an External Electrode Fluorescent Lamp (EEFL) provided at a fixing member.
As shown in FIG. 2, the CCFL fixed to a fixing member has two lamps 50 as one unit, and is provided with one rubber holder 60 for protecting a soldering part of the lamps 50. The two lamps 50 and the one rubber holder 60 are mounted in a side support 70, and are fixed on the lower cover 40.
The EEFL is composed of an upper side support and a lower side support 80a. As shown in FIG. 3, a common electrode holder 90 is mounted on the lower side support 80a so as to couple one lamp 50a. The lamp 50a is inserted into the common electrode holder 90, and then the upper side support (not shown) is coupled to the common electrode holder 90. Then, the common electrode holder 90 is entirely fixed onto the lower cover.
Here, the lower side support 80a may include a printed circuit board (PCB) serving as an electrode PCB and having a conductive wire 81, common electrode holders 90 fixed onto the PCB by a soldering process and coupling the lamps 50a, and a connector (not shown) connected to the conductive wire 81 on the PCB so as to supply a voltage to the lamps 50a coupled to the common electrode holders 90.
When the EEFL is driven by using the electrode PCB, an insulation sheet has to be implemented so as to insulate between the conductive wire 81 to which a high voltage is applied, and the lower cover, and so as to obtain a safety distance therebetween. This may cause additional costs.
Since the electrode PCB is large in case of a large LCD device, a problem that the electrode PCB is bent may occur. Furthermore, when the electrode PCB is penetrated or punched, foreign materials may occur due to a material characteristic of the electrode PCB.
Furthermore, when the common electrode holders, or grips for coupling the lamps are fixed onto the electrode PCB, the grips have to be mounted on corresponding regions on the electrode PCB, and then have to undergo a surface mount process (SMT) such as a soldering process. In this case, the grips may be distorted at the corresponding regions.